WASHINGTON - There is no disputing that Mitt Romney's speech on religious diversity and tolerance Thursday was powerful in its appeal to Americans to look beyond his Mormon religion when they cast their ballots for president. But even at his most eloquent, the Republican candidate failed to tackle the most important part of his problem.

While he unequivocally stated his belief in the divinity of Jesus, he did nothing to confront those who think Mormonism is somehow weird or cultlike. He approached the speech as if the main question was his own character, not the tenets of his religion.

That failure may be more important than anything he said during the address at Texas A&M University.

"I don't think the problem goes away for the people who are concerned about Mormonism," said Stuart Rothenberg, a respected nonpartisan political analyst here. "He can't change Mormonism and he can't make it more palatable and he can't make people more comfortable with it."

He added, "I don't see how the speech addressed that issue. People are not really saying they don't trust him or they don't trust his values. It's not about that at all."

In fact, the speech may deepen the distrust because it unleashed a torrent of news stories focusing on aspects of Mormon beliefs that differ sharply from mainstream Christian religions.

"To say the Garden of Eden was in Missouri just sounds odd to some people," said Rothenberg, citing one area where the Church of Jesus Christ of Latter-Day Saints - the official name of the Mormon church - differs with other religions.

"Intellectually, it was a very fine speech but it doesn't really put to rest the emotional, deep-seated questions that a lot of evangelicals have," said Michele Dillon, a professor at the University of New Hampshire in Durham and an expert on religion and politics.

"He was very clear in stating what he believes about Jesus. But then I felt some of the power was taken away by his next sentence when he said my church's beliefs about Christ may not be the same as those of other faiths," said Dillon. "Well, that's the whole point... That's what causes all the controversy - is it the same Jesus?"

Mark Rozell, a professor at George Mason University and an expert on the Christian Right, said an offshoot of the speech may be to "just increase the profile of exactly those matters that make some voters uncomfortable with him."

The speech, of course, brought repeated comparisons with John F. Kennedy's historic speech Sept. 12, 1960 to the Greater Houston Ministerial Association when he was trying to overcome opposition to the election of the first Catholic president. But Rozell noted some important differences between the two speeches separated by 47 years.

One important difference is that there were more than 30 million Catholics in the United States then and even those who feared a Catholic in the White House probably personally knew a Catholic. Today, there are only an estimated 6 million Mormons in the country today and their beliefs are a mystery to most Americans.

"Even though there were questions about the electability of Catholics, the reality was that Catholics were part of the mainstream of American society," said Rozell. "There are still a lot of people who look at Mormons as cultlike or a little strange. This is still a problem for Romney to overcome."

That point is made powerfully by an August survey by the Pew Research Center. It found that barely half the public (49 percent) said they know "a great deal" or "some" about the Mormon religion, and only 53 percent of the public have a favorable opinion of Mormons. Almost a third said they doubted that Mormons are Christians. White evangelical Protestants - the target of Romney's speech and a power in the Republican party - were the most skeptical, with 36 percent of them saying they would be reluctant to vote for a Mormon.

The only other religious group to fare worse were Muslims. "The only two toxic answers are Muslim and Mormon," noted Rozell.

In New Hampshire, Dillon said that voters who have watched Romney operate as governor of neighboring Massachusetts will be less swayed by doubts about his religion.

"They know that he was a very good executive," she said. "And he kept that executive tone in this speech, so his competence, his delivery, and his clarity all got reinforced. But I don't think the religious statement is going to change too many minds here."